Furnace for heat treatment of metal sheets



May 23, 1933. H. H. HARRIS FURNACE FOR HEAT TREATMENT OF METAL SHEETS Filed July 21, 1931 2 Sheets-Sheet 1 INV ENTOR 6 8/70 A4 Herr/Li ATTORNEYS May 23, 1933. H, H. HARRIS FURNACE FOR HEAT TREATMENT OF METAL SHEETS Filed July 21, 1931 2 Sheets-Sheet 2 INVENTOR A or/ /b.

ATTORNEYS.

Patented May 23, 1933 HENRY H. HARRIS, OF DETROIT, MICHIGAN FURNACE FOB HEAT TREATING! OF METAL SHEETS Application filed my 21,

My invention relates to furnaces for heat treatment of metal sheets and particularly to a paratus for travelling the sheets through t e furnace.

According to my invention the sheets are supported on cross beams, preferably I- beams, of heat-resistant alloy and are advanced by up-and-forward bodily movement of the cross beams, which are then given down-and-back movement preparatory to their next forward movement for sheet advancement. Alternate beams may be given such movements in alternation or movable beams may be arranged to alternate with stationary beams, the sheets resting on the stationary beams during the backward movement of the movable beams and being lifted therefrom during the forward movement of the movable beams, and thereby intermittently advancing so that the sheets introduced at one end of the furnace may be passed therethrough by intermittent steps andbe subjected to annealing, etc. heat treatment during the passage through the furnace, and ultimately delivered through the opposite exit end of the furnace. The beam actuating mechanism is desirably located outside the furnace walls where it isnot exposed to the high temperature in the furnace. One of the ob ects of the invention is to make rovision' for the beams or extensions thereo projecting through the furnace walls, to be given bodily movement in the manner above referred to, and at the same time to make pro vision for preventing undue loss of heat through the furnace walls incident to such beam movement. I

In the drawings forming a part of this specification I have illustrated two forms of beam and beam actuating arrangements for furnaces of the type above referred to.

In said drawings,

Figure 1 is a horizontal and Fig. 2 a ver tical section of one form of beam and beam actuating apparatus.

Figs. 3 and 4 are end and side detail views respectively of the beam moving cam for use therewith;

Figs. 5 and 6 are views similar to Figs. 1

1931. Serial No. 552,112.

and 2 but showing a modified form of beam actuatin mechanism, and

Figs. and 8 are end and side elevations respectively of the beam moving cam and shaft made use of with the arrangements of Fi s. 5 and 6. o

n Figs. 1 and 2, reference character 10 represents a bodily movable grate bar or beam extending transversely of the furnace, the side walls whereof are indicated at 12, 12. The beams 10 are preferably of a length I somewhat less than the interior width of the furnace so that they can be readily inserted. Beams 10 preferably have square ends 14, 14' by which they are connected by a'preferably telescoping oint connection to the preferably hollow members 16, 16', which extend through the furnace walls and can be inserted from the'outside into the openings 18, 18' therein, and engaged with beams 10. Actuating of beams 10 may be directly through devices engaging the heat resistant alloy members 16, 16, but preferably for the purpose of saving expensive alloy and reducing metal requiring replacement at any time, separate outside members 20, 20', which need not be of heat resistant alloy, are provided for this purpose, and have a telescoping connection with the members 16, 16, keys or splines 22 being provided to prevent turning of these parts relative to one another.

The telescoping arrangement of parts described is strong and stiff, and any movement of the members 20 and 16 is communicated to and shared by the beams 10.

The means illustrated for actuation of beams 10 comprise shafts 24, 24 located 0ut-,

The openings :18, 18 in the furnace walls are of suitable dimension to permit the dein liners 34, 34', which may be of heat resist-' ant alloy metalin sheet form, enclosing? and reinforcing the asbestos disks 32,32.

Within the furnace walls 12, 12 I provide hollow members 36, 36 which may be of cast heat resistant alloy and. which are preferably built into the furnace wall when the latter is constructed, and provide lateral extensions or recesses 38, 38' projecting be 0nd the-wall'openings 18, 18' and into whic recesses 38,38 the asbestos disks 32,32 extend,

but their extension into the recesses 38, 38 is not so great as to prevent thedescribed movement being imparted to the beams 10 and connected arts. The clearance between the faces 0 the disks 32,32 and the walls of the recesses 38, 38' may be as small as desired so lon as-the described relative movement is rea ily possible, and such clearance ma readily be small enough to effectively bloc the exit of heat and furnace gas from the furnace interior. a

In the. form shown in Figs. 5-8 the beams 10' are provided at their ends with knuckle members 40, 40, each having a lower ball portion 42,42 and an upper ball portion,44, 44. These ball portions are received in elongated sockets 46, 46' and 48, 48'. in the lever mem'-.

bers 50, 50' which levers are universally pivotally supported at 52, 52' within the furnace walls 54', 54'. The lever members 50, 50' are provided with wear pieces 56, 56' extending upward on their outer endsto coact with cams 58, 58' by which the levers are actuated. The cam tracks in the cams 58, 58' may be of the plain circumferential variety as indicated at 60 (Fig. 8) and so adapted to rock levers.

50, 50 to move the beams 10' up and down. In such case, in order to impart back" and forth movement to the beams 10' through lever members 50, 50' the shaft 62, in addition to being rotated for turnin the cams 58, 58' therewlth, is also arranged to have a longitudinal axial movement of translation in a Fig. 4 can be used with the arran enient of Figs. 5 and 6, in which case the ongitudibar at the outside of the furnace walls, power transmission means outside of said walls at opposite ends of the grate bars, and actuating means operated-by said powertransmission means and individual to and coacting with the thrust receiving means at the opposite ends of each grate bar, each actuatmg means operating on the thrust receiving means thereof at the same point to cause'a grate bar movement having both a vertical and horizontal component for producing intermittent progressive movement of articles onthe ate bar to be heat treated.

2. The com iinatio'n as claimedin claim 1 in which the thrust receivingmeans comrise lever members pivotally mounted in t e furnace walls. V

3. The combination as claimed in claim 1 in which the grate bars have lever members universally mounted in the furnace walls, the parts including ball and socket portions, said socket portions being elongated.

4. The combination as claimed in claim 1 in which the thrust receiving means are formed as projecting extensions of the grate bars and the power transmission means comprise shafts extending longitudinally of the furnace, the actuatingmeans being mounted on the shafts and engaging the extensions of I the grate bar. I

5. A grate bar extending transversely through andhaving extension ortions projecting beyond the side walls 0 the furnace, and cams located outside the furnace and coacting with'the extension ortions of the grate bar for imparting bodi y movement to the grate bar adapted to produce intermittent progressive movement of articles supported thereon to be heat treated.

6. In a heat treating furnace, side walls provided with apertures, rate bars having extensions assing throug said apertures, means outside the furnace walls engaging said extensions and su porting said grate bars for im arting to t e grate bars bodily movement or advancing articles supported thereon to be heat treated,'and means in the furnace walls disposed about the grate bar extension for substantially sealing the furnace walls against egress of heat and furnace gases and preventing axial movement of said ate bars relative to said movement impart- 7 In a heat treating furnace, side walls having apertures therein, recesses in said ing means while permitting the described movement of the grate bars.

walls in extension of said apertures, grate bars projecting through said apertures, and members of substantially disk form disposed upon and moving with the grate bars, said disks substantially closing the apertures and extending into the recesses associated with said apertures whereby the grate bar can be bodily moved in the apertures in the walls so as to produce a progressive advancement of work supported thereby to be heat treated and at the same time the furnace wall is sub-' stantially sealed against egress of heat and furnace gases.

8. In a heat treating furnace, a series of grate bars extending transversely thereof,

apertures provided in the furnace -walls through which extensions of the grate bars project, and means for impartin up and forward and down and back bodily movement to the grate bars comprising shafts outside the furnace walls and arranged substantially parallel thereto and cams with twisted grooves upon said shafts and coacting with said grate bars as the shafts are rotated.

9. In a heat treating furnace, a series of grate bars, means projecting through the furnace walls for imparting bodily movement to the grate bars, and means for actuating said movement imparting means outside the furnace walls and comprising longitudinally reciprocable shafts and cam members thereon having a plaincylindrical groove eccentrically related to the axis of the shaft and coacting with said grate bars.

10. In a heat treating furnace, a series of grate bars extending transversely thereof, each having at opposite ends thrust receiving means extending outside of the furnace walls, and means forimparting up and forward and down and back bodily movement to the grate bars comprising ower transmission means outside of the urnace walls at opposite ends of the grate bars and cams operated by said transmission means and coacting with and individual to the thrust receiving means of each of said grate bars.

11. In a heat treating furnace, grate bars extending transversely thereof, thrust receiving means at the outer ends of each ate bar, and cam means at the outside 0 the furnace individual to and coacting with each thrust receiving means, each cam means having an interengaging relation with the thrust receiving means thereof at the same point to cause a grate bar movement having both a vertical and horizontal component without disengagement of the cam means and the thrust receiving means from each other.

12. The combination as defined in claim 11 comprising means in the furnace walls for preventing axial movement of the grate bars relative to the cam means.

In testimony whereof, I have signed my name hereto.

I HENRY H. HARRIS. 

